How to break a reference chain error in Jackson? (StackOverflowException error)

Java Conceptuel Diagram


When trying to serialize a POJO with Jackson's ObjectMapper, you may get this StackOverflowException error:

Infinite recursion (StackOverflowError) (through reference chain: 

This article explains to you how you can resolve it.

Why does this error happen?

This error happens when you have a many-to-many relationship, for instance when:

  • a Person has a list of Groups
  • and the Group has a list of Persons.

If we try to serialize these POJO with Jackson's ObjectMapper, we get a circular reference when:

  • a person that belongs to a group
  • is also on the group's list of people.


The techniques that you can use to break a circular references are:

Object Reference Identity

Through the Object Reference Identity 1), you can define your data and let Jackson handle the circular reference by:

  • writing the object Id
  • in place of the whole object.

Identifier Definition with the @JsonIdentityInfo

@JsonIdentityInfo is a class annotation that serializes a POJO by id, the second and next time that the same object is encountered. It does not serializing the complete object.

  generator = ObjectIdGenerators.PropertyGenerator.class, 
  property = "id",
  scope = User.class
public class User {

Note when @JsonIdentityReference is added, the POJO is serialized by id the first time it is encountered. Example:

@JsonIdentityReference(alwaysAsId = true)

Relation Definition with @JsonManagedReference and @JsonBackReference

You can annotate the property with:

  • @JsonManagedReference: the forward part of the reference, the one that gets serialized normally.
  • @JsonBackReference: the back part of the reference (omitted from serialization).

Excluding a property

If you exclude a property from the chain, you break the chain. See this article that lists all possibilities: How to exclude properties from the JSON output with Jackson?

Discover More
Java Conceptuel Diagram
What is the Java Jackson Library? (Parser/Writer)

Jackson is a parser and generator library that permits the creation of: textual formats (Json, Xml, Csv, ...) from Java objects. Java objects from textual data In other terms, it's a serialization/deserialization...

Share this page:
Follow us:
Task Runner